Embodiments relate to a semiconductor device and a method for forming the same, and more particularly to a semiconductor device for blocking a moving path of electrons between neighboring buried gates, and a method for forming the semiconductor device.
As the size of semiconductor devices continues to shrink, a recessed wordline or buried wordline structure in which a semiconductor substrate is etched in a manner that a recess is formed in the semiconductor substrate, has recently been proposed to improve refresh characteristics.
Application of the recessed wordline or buried wordline structure to semiconductor devices, has resulted in a reduction in the size of wordline area. However, the semiconductor device may operate abnormally due to the occurrence of an RC delay. In order to solve the abnormal operation of the semiconductor device, a wordline is generally formed of a metal material.
However, assuming that the wordline is formed of metal, a work function of the wordline is changed, so that electrons may become trapped onto the surface of Si/SiO2 material of the semiconductor substrate according to on and off operations of the wordline, and then released from the Si/SiO2 surface.
Specifically, electrons trapped onto the semiconductor substrate start motion when a neighbor gate or a passing gate is repeatedly turned or off, such that data of an off-state magnetic cell is changed to another.
According to the phenomenon described above, data stored in the off-state cell may be changed according to repetition of the on/off operation of neighboring wordlines, such that defective semiconductor devices occur, resulting in reduction of reliability of the semiconductor devices.